The Morphology/Immunology/Biochemistry Section will provide the various projects in the program with the necessary expertise, facilities, and support to perform routine light microscopy, immunofluorescent microscopy and any other routine or specialized morphological, pathological and immunohistochemical support required. The Molecular Biology Section will supply the program with the capabilities to prepare and test the role of specific domains of the connexin proteins on their function and pH sensitivity. Specifically the responsibilities of the Molecular Biology Section of Core C will include the growth and purification of DNA; site-specific mutagenesis of the connexin cDNA's; production of cRNA and checking of the cRNA in vitro translation assays; DNA sequencing of mutagenized connexin and cDNA's preparation and microinjection of frog oocytes; and expression of connexins by transfection into mammalian cells in culture.